Adiponectin (Adp) is a cytokine secreted mainly by adipose tissue. The funcfon of Adp has attracted recent interest. Skeletal muscle satellite cells were separated from semitendinosus muscle of Wannanhua pig at 10 days of age. Muscle satellite cells were treated with 0, 1, 5 and 10 μg/mL recombinant adiponectin (rAdp)respectively for 12 h or 24 h. Adp, AdpR1, AdpR2, four isoforms of myosin heavy chain (MyHCI, MyHC2a,MyHC2b and MyHC2x), AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor alpha (PPARa) mRNA levels were determined by Real-time fluorescence quantitative RT-PCR. The results showed that: (1) mRNA expression of Adp and AdpR1 treated with 1 μg/mL rAdp was significantly increased,and AdpR2 mRNA expression was even significantly increased only at 24 h. But mRNA expression of Adp,AdpR1 andAdpR2 treated with 5 and 10 μg/mL rAdp were lower; (2) mRNA expression of MyHC1 and MyHC2x treated with 1 μg/mL rAdp were significantly increased, but MyHC2b mRNA expression was significantly decresed only at 24 h. mRNA expression of MyHC2b treated with 5 and 10 μg/mL rAdp was significantly decresed, but MyHC1 mRNA expression had no significant change, mRNA expression of MyHC2a treated with 10 μg/mL rAdp was significantly decresed. MyHC2x mRNA expression treated with 5 μg/mL rAdp was incrcsed significantly. (3) mRNA expression of AMPK treated with 1, 5 and 10 μg/mL rAdp was significantly increased only at 12 h. However, the low rAdp doseage group had higher AMPK mRNA level. PPARa mRNA expression was significantly increased treated with 1 μg/mL rAdp. But high rAdp dosage groups had no this effects. The results suggest that the function of adiponectin to skeletal muscle may be related to activating both AMPK and PPARa signal pathways by binding adiponectin receptor. Adiponectin can change composition of muscle fibers by increasing MyHC1, MyHC2a and MyHC2x, and decreasing MyHC2b gene expression.%脂联素(Adp)是主要由脂肪组织分泌的细胞因子,其作用受到普遍关注.选择10 d皖南花猪半腱肌分离骨骼肌卫星细胞,用不同浓度(0、1、5和10μg/mL)的重组脂联素(rAdp)分别处理12和24 h,采用荧光定量PCR检测骨骼肌细胞中脂联素(Adp)、脂联素受体1(AdpR1)、脂联素受体2(AdpR2)和肌球蛋白重链(MyHC),4种亚型MyHC1、MyHC2a、MyHC2b、MyHC2x,以及AMP激活蛋白激酶(A MPK)、过氧化物增殖剂活化受体α(PPARa)的基因表达.结果显示:(1)1μg/mL rAdp处理后,Adp和A dpR1基因表达量极显著增加,AdpR2的表达量在处理24 h极显著增加.而5和10 μg/ml组Adp、AdpR1和AdpR2的表达量低于对照组;(2)1μg/mL rAdp处理显著上调MyHC1和MyHC2x的基因表达量,而MyHC2b的表达量则在处理24 h极显著下降.5和10μg/mL rAdp处理显著下调MyHC2b的基因表达量,而对MyHC1无显著影响.10μg/mL处理后MyHC2a的表达量极显著下降,5μg/mL处理后MyHC2x的表达量极显著增加;(3)1、5和10 μg/mL rAdp处理12 h后,AMPK基因表达量极显著高于对照组,但是低剂量组具有较高的基因表达量.1μg/mL rAdp处理12和24 h,PPARa基因表达量极显著高于对照组,然而高剂量组没有这种效应.结果提示,Adp作用于骨骼肌,可能是与受体结合后通过AMPK和PPARa两个信号途径,提高MyHC1、MyH2x和降低MyH2b基因表达量,改变肌纤维组成.
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